1. Field of the Invention
The invention relates to a mobile telephone.
2. Description of Related Art
Telephone users often have the desire to share their calls with others. In the prior art, this desire has been addressed by various solution. First of all telephone sets have been provided with loudspeakers to make the sound of an incoming call heard throughout the room in which a telephone set is located. If the user wants to share the call with a number of people in the room, he or she switches on the loudspeakers and possibly a microphone.
In another solution, the telephone network provides for conference calls. A conference call connects a group of more than two users. In a conference call the telephone network routes sound from each member of the group to all other members of the group. Basically, the conference call solution and the loudspeaker solution serve two different situations: one in which participants in a call are located in different locations and another in which a number of participants are located in the same room. Of course, the two can be combined when a sub-group of participants in a conference call are gathered in a single room. The loudspeaker solution has the advantage that it does not require additional connection costs. Also it does not have the complexity involved with establishing conference calls (finding telephone number of participants, dialing etc.).
Both the loudspeaker solution and the conference call solution could be applied to mobile telephones as well. However, the loudspeaker solution is less attractive for mobile telephones, first of all because loudspeakers tend to be bulky and secondly because, unlike conventional telephones, mobile telephones tend to be used in public spaces where speaking conversations out loud is undesirable. Thus, for mobile telephones effectively only the conference call solution is available, at the expense of greater complexity to establish the call and increased connection costs.